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Study on Heat Transfer Characteristics of Gaseous Flows in Micro Channels

微通道内气体流动传热特性研究

基本信息

批准号：
16560189
负责人：
ASAKO Yutaka
金额：
$ 2.37万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560189/
关键词：
Micro-channel Gaseous flow Heat transfer Parallel plate channel Micro tube

项目摘要

Fabrication of small devices has increased the need for understanding of fluid flow and heat transfer in micro geometries. The pressure drop of fluid flow in a micro channel is quite large because of the friction loss. In case of gaseous flows, gas expands along the channel and flow is accelerated in the channel. This results in temperature fall due to the energy conversion from the internal energy to the kinetic energy. Heat transfer characteristics of gaseous flow in a micro channel might differ from that of incompressible flows. However, there is no parametric study on the heat transfer characteristics of gaseous flow in micro-channels. This is the motivation of the present study. Objectives of the present study are; 1. To obtain the heat transfer characteristics of gaseous flow in micro channels. 2. Verification of the gas temperature at the channel exit that has been numerically obtained in a foregoing research.(1) The computations are performed for channels with constant heat flux which ranges from 10^2 to 10^4W m^<-2> and with the constant wall temperarure. The channel height ranges from 10 to 100μm and the aspect ratio of the channel height and length is fixed at 200. The heat transfer characteristics of gaseous flow in a micro channel is obtained. The wall and bulk temperatures in micro-channels are compared with that of the incompressible flow in the conventional sized parallel plate channel. The heat transfer characteristics of a micro tube is also obtained.(2) The gas temperature at the exit of a micro tube was measured by a laser-induced fluorescence method and the comparisons were made with numerically obtained temperature in a foregoing research. And the availability of the laser-induced fluorescence method for temperature measurements is discussed.

小型器件的制造增加了对微几何形状中流体流动和传热的理解的需要。微通道内流体流动的阻力损失很大。在气流的情况下，气体沿着通道膨胀，并且流动在通道中加速。由于从内能到动能的能量转换，这导致温度下降。微通道内气体流动的传热特性可能不同于不可压缩流动。然而，目前还没有微通道内气体流动换热特性的参数化研究。这就是本研究的动机。本研究的目的是：1。获得微通道内气体流动的换热特性。2.验证在前面的研究中数值获得的通道出口处的气体温度。(1)计算是在热流密度为10^2 ~ 10^4W·m^-1<-2>，壁温为恒定的情况下进行的。通道高度范围为10至100μm，通道高度和长度的纵横比固定为200。得到了微通道内气体流动的换热特性。将微通道内的壁温和体温与常规尺寸平行板通道内不可压缩流的壁温和体温进行了比较。同时也得到了微管道的传热特性。(2)采用激光诱导荧光法测量了微管出口处的气体温度，并与前面研究中数值计算得到的温度进行了比较。讨论了激光诱导荧光测温方法的可行性。